This is a clinical research project in the odontologic special field; periodontology. Periodontitis affects > 50% of all persons over 40 years-of-age, whereof 5 - 10% is prone to loose one or more teeth due to the disease. In Norway, less than 40% of the periodontal treatment costs are carried (refunded) by the public. The proportion of personal expenses vs. public spending depends on how serious the periodontitis is diagnosed, and on the individual treatment provided. In addition comes expenses connected to the restoration of the dentition when teeth are lost as a consequence of the disease, and therefore the social, personal and economical consequence of serious tooth loss can be devastating to the patient.